What is the compound name for the carboxyl functional group?

The carboxyl functional group is characterized by its distinctive structure, which includes a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group (-COOH). This functional group is a defining feature of carboxylic acids, which are organic compounds that contain one or more carboxyl groups.

Carboxylic acids are known for their acidic properties due to the ability of the hydrogen atom in the hydroxyl part of the carboxyl group to dissociate, releasing a proton (H+) into solution. This is a fundamental aspect that distinguishes carboxylic acids from other functional groups.

In contrast, amino acids contain both an amino group and a carboxyl group, thiols contain a sulfur atom bonded to a hydrogen atom, and organic phosphates have a phosphate group. None of these other functional groups share the unique properties or structure of the carboxyl functional group, reinforcing that the correct compound name is indeed carboxylic acid.